I've been using Nikon for 3+ years and have been mostly pleased with the Nikon system. Tons of lens options, even more accessories, and plenty of options for buying and selling used. However, Nikon really ticked me off with the D600 sensor oil/dust problem that they "fixed" by releasing the D610- meanwhile I was stuck with a D600 sensor that looks like pepper after a week of shooting. I have since parted ways with the D600, so I'm left with D7000 and D7100 bodies (both APS-C format). I've gotten in pretty deep with Nikon stuff: Sigma 15mm fisheye, Nikkor 24-85mm VR, Tamron 17-50mm 2.8, 50mm 1.8, 85mm 1.8, and the big-daddy 70-200mm 2.8 VRII. I also have invested in three Nikon speedlights and nikon-specific radio triggers. The rest of my gear doesn't care what camera brand I'm using. I am thiiiis close to pulling the trigger on the D610 and the 16-35mm f4.

Having said all this, I am having thoughts of switching to Fuji. The X-T1 has me drooling and the reviews on Fujinon lenses are usually very stellar. So are Fujinon lenses on par with similar offerings from Nikon, Sigma, et al? I can certainly re-create my current lens profile with Fujinon lenses, especially with the 16-55 and 50-140 2.8 lenses due out this year. I'm a little worried that Fuji has gone whole-hog into the APS-C format sensor, but they just seem to keep getting better- almost up to full-frame quality. Will I regret limiting myself to APS-C? Weight and size are secondary to image quality in my book. I won't lie, the smaller form factor of the Fuji gear is appealing, but not if IQ suffers.

So what say you, Fuji fans? Do I drop Nikon and go Fujifilm?

If you don't know why you better should not switch. If size is not a big deal I would rather get a Nikon full frame DSLR plus some good lenses.